Blar i forfatter "Fossen, Haakon"

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    • Adamastor – an ocean that never existed? 

      Konopasek, Jiri; Cavalcante, Carolina; Fossen, Haakon; Janoušek, Vojtěch (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-08)
      <p>Existing models of tectonic evolution of the Neoproterozoic orogenic system rimming the shores of the South Atlantic Ocean (the Araçuaí–Ribeira–Congo and Dom Feliciano–Kaoko–Gariep belts) interpret the belts as subduction-related orogens and emphasize the role of the “Adamastor Ocean” in their pre-collisional evolution. A critical problem in such an interpretation is the confined nature of the ...

    • Comment to “Neoproterozoic magmatic arc systems of the central Ribeira belt, SE-Brazil, in the context of the West-Gondwana pre-collisional history: A review” 

      Fossen, Haakon; Meira, Vinicius T.; Cavalcante, Carolina; Konopásek, Jiří; Janoušek, Vojtěch (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-25)

    • A critical discussion of the subduction-collision model for the Neoproterozoic Araçuaí-West Congo orogen 

      Fossen, Haakon; Cavalcante, Carolina; Konopásek, Jiří; Meira, Vinicius T.; Paes de Almeida, Renato; Hollanda, Maria Helena BM de; Trompette, Roland (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-22)
      The Neoproterozoic Araçuaí-West Congo orogen in Brazil and Congo represents a branch of the Brasiliano/Pan-African orogenic system that is considered to terminate northward into a confined cratonic environment defined by the horseshoe-shaped pre-Atlantic São Francisco-Congo craton. The prevailing interpretation is that this orogen formed as a result of 50 m.y. of subduction leading to a classical ...

    • Quartz textural analysis from an anastomosing shear zone system: Implications for the tectonic evolution of the Ribeira belt, Brazil 

      Conte, Thailli; Cavalcante, Carolina; Lagoeiro, Leonardo Evangelista; Fossen, Haakon; Silveira, C.S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-18)
      Strain localization and influence of grain-size reduction processes were investigated from field and microstructural observations, and from quartz textural analysis using EBSD, in rocks deformed along an anastomosing network of shear zones in the Ribeira belt in Brazil. Rocks deformed along the Lancinha shear zone (LSZ) display high percentage of recrystallized grains, in which quartz recrystallized ...

    • TitaniQ temperatures and textural analysis as a record of the deformation history in a major continental shear zone system, Borborema Province, Brazil 

      Cavalcante, Carolina; de Jesus Costa, Juliana; Lagoeiro, Leonardo; Fossen, Haakon; Lee, Amicia; Archanjo, Carlos; Vizeu, Roberto (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-01)
      We combine quartz textural analysis with Titanium-in-quartz (TitaniQ) geothermometry to investigate the late stages of deformation in mylonitic rocks from the Sucuru dike swarm in the Borborema Province. The wide range in TitaniQ temperatures (>340 to 740 °C) closely related to grain sizes are attributed to inefficient Ti resetting during bulging (BLG) and subgrain rotation (SGR) recrystallization. ...